How is the ielts reading exam marked?

I ve been taking practice test but I don t know how the exam is marked, do i have to write the exact same answer on the answer sheet or anything close to it.
cause in some cases they use more than a word to answer while i ve used less words but with the same meaning does that count or? and for some questions there are more than one answer for example “this and that” what if I only write one down? does that makes it wrong?
thank you I am taking the academic test, i don’t know if its any different but I thought I needed to mention it